005:Maybe you could play the music anyway. I like the idea that every vehicle has a song that plays on the radio when people are in it. You've already done that to most of the vehicles, why not the rest?
To be clear, it doesn't have to play in a "bongo" for it to be funny. It's still funny if it plays in the sub. That's why I put "bongo/sub" in my suggestion... but still, it's your baby, so I won't try to convince you any further.